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        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 187 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 6)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 15)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 289)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 5)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 7)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 5)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Case Reports in Veterinary Medicine     Open Access  
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 1)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 7)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 4)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 3)
Equine Health     Full-text available via subscription  
Equine Veterinary Education     Hybrid Journal   (Followers: 7)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 2)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
ISRN Veterinary Science     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 9)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 21)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 4)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Hybrid Journal   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 9)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Kufa Journal For Veterinary Medical Sciences     Open Access  
Livestock     Full-text available via subscription   (Followers: 1)

        1 2     

Journal Cover Veterinary Microbiology     [SJR: 1.221]   [H-I: 75]
   [10 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [2585 journals]
  • Evidence for the vertical transmission of Sunshine virus
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Timothy H. Hyndman , Robert S.P. Johnson
      Sunshine virus is a paramyxovirus of pythons associated with neurorespiratory disease and mortalities. This report provides evidence for its vertical transmission. In a collection of over 200 Australian pythons, a dam and a sire, both carpet pythons (Morelia spilota), were PCR-positive for Sunshine virus at a time when the dam was likely to have been gravid. A clutch of 21 eggs was laid and three non-viable eggs were tested for the presence of Sunshine virus by PCR. One egg had been incubating for 34 days while the other two had been incubating for 49 days. The surface of all three eggs was negative for Sunshine virus but swabs of the allantois and amnion were positive in all three eggs. Embryo tissue samples were tested from the two 49 day old eggs. From one embryo, a sample of brain and a pooled sample of lung, liver, kidney and intestine were positive, while for the other embryo, a pooled sample of lung, liver, kidney, intestine and brain was positive. Fourteen of the 21 eggs hatched and all hatchlings were tested by PCR at least once between the ages of 53 and 229 days old. All hatchlings were PCR-negative for Sunshine virus.


      PubDate: 2015-01-16T17:22:48Z
       
  • Evaluation of the effect of short-term treatment with the integrase
           inhibitor raltegravir (Isentress™) on the course of progressive
           feline leukemia virus infection
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Andrea Boesch , Valentino Cattori , Barbara Riond , Barbara Willi , Marina L. Meli , Katharina M. Rentsch , Margaret J. Hosie , Regina Hofmann-Lehmann , Hans Lutz
      Cats persistently infected with the gammaretrovirus feline leukemia virus (FeLV) are at risk to die within months to years from FeLV-associated disease, such as immunosuppression, anemia or lymphoma/leukemia. The integrase inhibitor raltegravir has been demonstrated to reduce FeLV replication in vitro. The aim of the present study was to investigate raltegravir in vivo for its safety and efficacy to suppress FeLV replication. The safety was tested in three naïve specified pathogen-free (SPF) cats during a 15 weeks treatment period (initially 20mg then 40mg orally b.i.d.). No adverse effects were noted. The efficacy was tested in seven persistently FeLV-infected SPF cats attained from 18 cats experimentally exposed to FeLV-A/Glasgow-1. The seven cats were treated during nine weeks (40mg then 80mg b.i.d.). Raltegravir was well tolerated even at the higher dose. A significant decrease in plasma viral RNA loads (∼5×) was found; however, after treatment termination a rebound effect was observed. Only one cat developed anti-FeLV antibodies and viral RNA loads remained decreased after treatment termination. Of note, one of the untreated FeLV-A infected cats developed fatal FeLV-C associated anemia within 5 weeks of FeLV-A infection. Moreover, progressive FeLV infection was associated with significantly lower enFeLV loads prior to infection supporting that FeLV susceptibility may be related to the genetic background of the cat. Overall, our data demonstrate the ability of raltegravir to reduce viral replication also in vivo. However, no complete control of viremia was achieved. Further investigations are needed to find an optimized treatment against FeLV. (250 words)


      PubDate: 2015-01-16T17:22:48Z
       
  • The protoxin Cry1Ac of Bacillus thuringiensis improves the protection
           conferred by intranasal immunization with Brucella abortus RB51 in a mouse
           model
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Edith González-González , Ana Lilia García-Hernández , Raúl Flores-Mejía , Rubén López-Santiago , Leticia Moreno-Fierros
      Brucellosis is a zoonotic disease affecting many people and animals worldwide. Preventing this infection requires improving vaccination strategies. The protoxin Cry1Ac of Bacillus thuringiensis is an adjuvant that, in addition to increasing the immunogenicity of different antigens, has shown to be protective in different models of parasitic infections. The objective of the present study was to test whether the intranasal co-administration of pCry1Ac with the RB51 vaccine strain of Brucella abortus confers protection against an intranasal challenge with the virulent strain B. abortus 2308 in BALB/c mice. The results showed that co-administration of pCry1Ac and RB51, increased the immunoprotection conferred by the vaccine as evidenced by the following: (1) decrease of the splenic bacterial load when challenged intranasally with the virulent strain; (2) greater in vivo cytotoxic activity in response to the transference of previously infected cells; (3) further proliferation of cytotoxic TCD8+ cells in response to stimulation with heat-inactivated bacteria; (4) increased production of TNF-α and IFN-γ; and (5) significant IgG2a response. These results indicate that the use of the Cry1Ac protein as a mucosal adjuvant via the intranasal route can be a promising alternative for improving current RB51 vaccine against brucellosis.


      PubDate: 2015-01-16T17:22:48Z
       
  • Genotype distribution of Mycoplasma hyopneumoniae in swine herds from
           different geographical regions
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Lucas F. Dos Santos , Srinand Sreevatsan , Montserrat Torremorell , Maria A.S. Moreira , Marina Sibila , Maria Pieters
      Genetic heterogeneity of Mycoplasma hyopneumoniae in pigs has been reported, however there has been limited reproducibility on the molecular methods employed so far. The aim of this study was to modify and standardize a high-resolution multiple locus variable number tandem repeat analysis (MLVA), to investigate the genetic variability of M. hyopneumoniae circulating in the United States of America (USA), Brazil, Mexico and Spain. The MLVA was standardized on the basis of the number of tandem repeats in two Mycoplasma adhesins, P97 and P146, which are proteins involved in the adherence of the pathogen to cilia. A total of 355 samples obtained from the four countries were analyzed. The Simpson's diversity index for the assay was D =0.976 when samples from all countries were combined. A large number of MLVA types (n =139) were identified, suggesting that multiple M. hyopneumoniae variants are circulating in swine. The locus P97 had 17 different types with 2–18 repeats. The P146 locus showed higher heterogeneity, with 34 different types, ranging from 7 to 48 repeats. MLVA types that presented more than 30 repeats in P146 were found in Spain and Brazil, while shorter repeats were observed in the USA and Mexico. This simplified MLVA method proved to be an efficient tool for typing M. hyopneumoniae with a high degree of stability, repeatability, and discriminatory power. In conclusion, M. hyopneumoniae showed a high variable number tandem repeat heterogeneity and this assay can be applied in molecular epidemiology investigations within farms and productions systems.


      PubDate: 2015-01-16T17:22:48Z
       
  • Antibodies to ovine herpesvirus 2 glycoproteins decrease virus infectivity
           and prevent malignant catarrhal fever in rabbits
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Cristina W. Cunha , Donald P. Knowles , Naomi S. Taus , Donal O’Toole , Anthony V. Nicola , Hector C. Aguilar , Hong Li
      Ovine herpesvirus-2 (OvHV-2) is the etiological agent of sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease of many species in the order Artiodactyla. Development of a vaccine is critical to prevent mortality. Because OvHV-2 has not been cultured in vitro, SA-MCF research is hindered by the lack of in vitro tools to study viral constituents and specific host immune responses. As an alternative, in this study the neutralizing activity of antibodies against OvHV-2 glycoproteins gB and gH/gL was evaluated in vivo using rabbits. OvHV-2-specific antibodies were developed in rabbits by immunization using biolistic delivery of plasmids expressing the genes of interest. A lethal dose of OvHV-2 was incubated with the antisera and then nebulized into rabbits. Virus neutralization was assessed by measuring infection parameters associated with the virus infectious dose. Anti-gB or anti-gH/gL antibodies alone blocked infection in five out of six rabbits (83%), while a combination of anti-gB and anti-gH/gL antibodies protected all six rabbits (100%) from infection. These results indicate that antibodies to OvHV-2 gB and gH/gL are capable of neutralizing virions, and consequently, reduce virus infectivity and prevent SA-MCF in rabbits. Thus, OvHV-2 gB and gH/gL are suitable targets to be tested in a SA-MCF vaccine aimed at stimulating neutralizing antibody responses.


      PubDate: 2015-01-16T17:22:48Z
       
  • Pestiviruses infections at the wild and domestic ruminants interface in
           the French Southern Alps
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Claire Martin , Véronique Duquesne , Gilbert Adam , Eric Belleau , Dominique Gauthier , Jean-Luc Champion , Claude Saegerman , Richard Thiéry , Eric Dubois
      In alpine pasture, interspecies transmission has recently been incriminated in the epidemiology of pestivirus infection. The aim of this study was to investigate pestivirus infections in wild and domestic ruminants sharing pastures in the French Southern Alps. Animal sera were screened for pestivirus antibodies against the pestivirus NS3 protein by a commercial blocking enzyme linked immunosorbent assay (ELISA). All 38 domestic herds tested were positive for pestivirus-specific antibodies. Individual sero-prevalence reached 76.5% (95% confidence interval [95% CI]: [74.2–78.8%]) of the 1383 sheep tested. For wild ruminants, 38.7% (95% CI: [33.8–43.9%]) of the 369 chamois tested, 28.7% (95% CI: [17.4–38.1%]) of the 72 roe deer, and 22.2% (95% CI: [6.5–37.9%]) of the 27 mouflons were seropositive. Virus screening was carried out on spleen samples from hunted wild animals (n =160) and from 15 domestic ruminants (clinically suspected to be persistently infected animals), by a conventional reverse transcription-polymerase chain reaction (RT-PCR). Three pestivirus strains were isolated from the sheep samples positive by RT-PCR. The viruses were classified in the BDV-3, BDV-Tunisian and BDV-6 genotypes. For the first time, one strain (RUPI-05 strain) was isolated from an alpine chamois and clustered in the BDV-6 genotype, showing in the 5′-UTR region 92% of identity with the ovine isolate from the same area. Thus, an active circulation of pestiviruses was demonstrated in both wild and domestic ungulates from the French Southern Alps. The results suggest that interspecies transmission between sheep and chamois probably occur.


      PubDate: 2015-01-16T17:22:48Z
       
  • Re-emerging of porcine respiratory and reproductive syndrome virus
           (lineage 3) and increased pathogenicity after genomic recombination with
           vaccine variant
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Wen Hui Lu , Hein Min Tun , Bao Li Sun , JianYui Mo , Qing Feng Zhou , Yu Xiu Deng , Qing Mei Xie , Ying Zuo Bi , Frederick Chi-Ching Leung , Jing Yun Ma
      Porcine reproductive and respiratory syndrome virus (PRRSV) was first reported in China since late 1995 and several variants were further reported in subsequence years, causing huge economic losses to the Chinese swine industry. To date, three major lineages (lineage 3, 5.1 and 8.7) of Type 2 PRRSV were reported in China based on our global genotyping. The present study provides the epidemiology of the PRRSV in South China based on the isolates collected during 2009–2012, indicating three lineages (lineage 3, 5.1 and 8.7) of Type 2 PRRSV were still circulating in this area. Our phylogenetic reconstruction indicated that lineage 3 re-emerged in 2010 formed a huge cluster with closely related to the 2004 isolates from Hong Kong. Furthermore, the inter-lineage genomic recombination between MLV vaccine strain (lineage 5) and a recently re-emerged lineage 3 virus (QYYZ) has also been found in a farm practicing MLV vaccination. Our in vivo experiment comparing the pathogenicity and clinical presentations among currently isolated viruses indicated that pigs infected with recombinant lineage 3 virus (GM2) showed persistent higher fever compared to pigs infected by its wild counterpart (QYYZ). This study enhanced our understanding on potential importance of the recombination of PRRSV along with their evolution.


      PubDate: 2015-01-16T17:22:48Z
       
  • A novel subpopulation of Salmonella enterica serovar Infantis strains
           isolated from broiler chicken organs other than the gastrointestinal tract
           
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Eiji Yokoyama , Naoshi Ando , Tomohiro Ohta , Akina Kanada , Yuh Shiwa , Taichiro Ishige , Koichi Murakami , Takashi Kikuchi , Satoshi Murakami
      Salmonella enterica subsp. enterica serovar Infantis strains were isolated from broiler chickens from six farms in Japan and the pathogenicity associated with the recently reported 280kbp mega plasmid was examined by possession of the plasmid and histopathology of tissues from these chickens. S. Infantis strains were isolated from 10 of 24 chickens. Phylogenetic, network and Bayesian cluster analyses were used to determine whether these strains were in the previously defined Clusters 1–5. Phylogenetic analysis classified the strains isolated in this study in two groups (Groups A and B). Both groups contained strains from gastrointestional contents, but only Group A also contained strains from spleen, liver, and lymphoid tissues. Histopathology showed suppurative splenitis in a spleen from which Group A strains were isolated. Although network and Bayesian cluster analyses were unable to differentiate Group A and B strains from the previously defined Clusters 1–5, population genetic analysis indicated that Group A was a different population from Cluster 5, indicating that Group A would be a subpopulation of Cluster 5. The irp2 gene, which is in the mega plasmid carried by a pathogenic S. Infantis strain recently isolated in Israel, was found in both Groups A and B strains and in the previously reported Clusters 4 and 5 strains. These results suggested that Group A would be a novel subpopulation of the previously defined Cluster 5, and presence of the mega plasmid may not be related whether S. Infantis strains can infect certain organs.


      PubDate: 2015-01-16T17:22:48Z
       
  • Assessment of immunogenicity and protective efficacy of Microsporum canis
           secreted components coupled to monophosphoryl lipid-A adjuvant in a
           vaccine study using guinea pigs
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Ludivine Cambier , Elena-Tatiana Băguţ , Marie-Pierre Heinen , Jérémy Tabart , Nadine Antoine , Bernard Mignon
      Microsporum canis is the most common dermatophyte in pets and is of zoonotic importance but currently there is no effective vaccine available to prevent dermatophytosis. The aim of this work was to assess the immunogenicity and protective efficacy of secreted components (SC) from M. canis adjuvanted with the monophosphoryl lipid-A (MPLA), in a vaccine study using the guinea pig as an experimental model. Animals were vaccinated with either the SC adjuvanted with the MPLA, the MPLA adjuvant alone or PBS three times at two-week intervals, until 42 days prior to M. canis infection. A blind evaluation of dermatophytosis symptoms development and fungal persistence in skin was monitored weekly. The antibody response towards the SC and the levels of Interferon (IFN)γ and Interleukin-4 expressed in peripheral blood mononuclear cells were assessed along or at the end of the study period respectively. The animals that received MPLA had a significantly lower clinical score than those inoculated with PBS. However, no significant difference was observed between the guinea pigs vaccinated with the SC adjuvanted with the MPLA and those having received MPLA alone. The results also showed that vaccination induced a strong antibody response towards the SC and an increase in IFNγ mRNA level. Our results show that the MPLA adjuvant used in this vaccine study can induce per se a partial protection against a M. canis infection. Although they induce a delayed-type hypersensitivity reaction in guinea pigs, the SC do not confer a protection under the present experimental conditions.


      PubDate: 2015-01-16T17:22:48Z
       
  • Diversity and health status specific fluctuations of intrauterine
           microbial communities in postpartum dairy cows
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): K. Wagener , I. Prunner , H. Pothmann , M. Drillich , M. Ehling-Schulz
      For the interpretation of clinical findings of endometritis and the development of disease prevention and intervention strategies a better understanding of the dynamics and interactions within intrauterine bacterial communities in healthy and diseased cows is required. To gain deeper insights into fluctuations within the uterine microbiota, intrauterine samples were collected from 122 cows at the day of calving, days 3, 9, 15, 21 and 28 postpartum. A total of 2052 bacterial isolates were identified by Fourier-transform-infrared spectroscopy. This culturomics-based approach showed that the aerobic uterine microflora comprised a huge diversity of bacteria belonging to 202 different species, representing 76 genera, with members of the genus Staphylococcus (24.2%) being predominant. On species level the uterine microflora was dominated by Trueperella pyogenes (13.2%), Escherichia coli (11.2%), Staphylococcus xylosus (5.4%), Bacillus pumilus (5.2%) and Streptococcus uberis (4.9%). Comparative analysis of uterine bacteria from cows with different vaginal discharge scores (VDS) revealed health status specific temporal microbial diversifications. Although the intrauterine flora of all VDS groups was dominated by T. pyogenes, E. coli and Staphylococcus spp., the relative number of bacteria differed between VDS groups. The presence of T. pyogenes on days 15 and 21 significantly increased the risk of VDS 2 and 3 at day 21, whereas Staphylococci at day 9 reduced the likelihood of VDS 3 (P <0.05). This study demonstrates that intrauterine bacterial infections are highly dynamic processes and that bacterial species follow specific patterns of progression, which require further research to decipher their potential role in uterine disease development.


      PubDate: 2015-01-16T17:22:48Z
       
  • The feline oral microbiome: A provisional 16S rRNA gene based taxonomy
           with full-length reference sequences
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Floyd E. Dewhirst , Erin A. Klein , Marie-Louise Bennett , Julie M. Croft , Stephen J. Harris , Zoe V. Marshall-Jones
      The human oral microbiome is known to play a significant role in human health and disease. While less well studied, the feline oral microbiome is thought to play a similarly important role. To determine roles oral bacteria play in health and disease, one first has to be able to accurately identify bacterial species present. 16S rRNA gene sequence information is widely used for molecular identification of bacteria and is also useful for establishing the taxonomy of novel species. The objective of this research was to obtain full 16S rRNA gene reference sequences for feline oral bacteria, place the sequences in species-level phylotypes, and create a curated 16S rRNA based taxonomy for common feline oral bacteria. Clone libraries were produced using “universal” and phylum-selective PCR primers and DNA from pooled subgingival plaque from healthy and periodontally diseased cats. Bacteria in subgingival samples were also cultivated to obtain isolates. Full-length 16S rDNA sequences were determined for clones and isolates that represent 171 feline oral taxa. A provisional curated taxonomy was developed based on the position of each taxon in 16S rRNA phylogenetic trees. The feline oral microbiome curated taxonomy and 16S rRNA gene reference set will allow investigators to refer to precisely defined bacterial taxa. A provisional name such as “Propionibacterium sp. feline oral taxon FOT-327” is an anchor to which clone, strain or GenBank names or accession numbers can point. Future next-generation-sequencing studies of feline oral bacteria will be able to map reads to taxonomically curated full-length 16S rRNA gene sequences.


      PubDate: 2015-01-16T17:22:48Z
       
  • Envelope protein complexes of Mycobacterium avium subsp. paratuberculosis
           and their antigenicity
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Fernando L. Leite , Timothy A. Reinhardt , John P. Bannantine , Judith R. Stabel
      Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease, a chronic enteric disease of ruminant animals. In the present study, blue native PAGE electrophoresis and 2D SDS-PAGE were used to separate MAP envelope protein complexes, followed by mass spectrometry (MS) to identify individual proteins within the complexes. Identity of individual proteins within complexes was further confirmed by MS upon excision of spots from 2D SDS-PAGE gels. Among the seven putative membrane complexes observed, major membrane protein (MAP2121c), a key MAP antigen involved in invasion of epithelial cells, was found to form a complex with cysteine desulfurase (MAP2120c). Other complexes found included those involved in energy metabolism (succinate dehydrogenase complex) as well as a complex formed by Cfp29, a characterized T cell antigen of Mycobacterium tuberculosis. To determine antigenicity of proteins, Western blot was performed on replicate 2D SDS-PAGE gels with sera from noninfected control cows (n =9) and naturally infected cows in the subclinical (n =10) and clinical (n =13) stages of infection. Clinical animals recognized MAP2121c in greater proportion than subclinical and control cows, whereas cysteine desulfurase recognition was not differentiated by infection status. To further characterize antigenicity, recombinant proteins were expressed for 10 of the proteins identified and evaluated in an interferon-gamma (IFN-γ) release assay as well as immunoblots. This study reveals the presence of protein complexes in the cell envelope of MAP, suggesting protein interactions in the envelope of this pathogen. Furthermore the identification of antigenic proteins with potential as diagnostic targets was characterized.


      PubDate: 2015-01-16T17:22:48Z
       
  • Two different genotypes of H1N2 swine influenza virus isolated in northern
           China and their pathogenicity in animals
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Huanliang Yang , Yan Chen , Chuanling Qiao , Chuantian Xu , Minghua Yan , Xiaoguang Xin , Zhigao Bu , Hualan Chen
      During 2006 and 2007, two swine-origin triple-reassortant influenza A (H1N2) viruses were isolated from pigs in northern China, and the antigenic characteristics of the hemagglutinin protein of the viruses were examined. Genotyping and phylogenetic analyses demonstrated different emergence patterns for the two H1N2 viruses, Sw/Hebei/10/06 and Sw/Tianjin/1/07. Sequences for the other genes encoding the internal proteins were compared with the existing data to determine their origins and establish the likely mechanisms of genetic reassortment. Sw/Hebei/10/06 is an Sw/Indiana/9K035/99-like virus, whereas Sw/Tianjin/1/07 represents a new H1N2 genotype with surface genes of classic swine and human origin and internal genes originating from the Eurasian avian-like swine H1N1 virus. Six-week-old female BALB/c mice infected with the Sw/HeB/10/06 and Sw/TJ/1/07 viruses showed an average weight loss of 12.8% and 8.1%, respectively. Healthy six-week-old pigs were inoculated intranasally with either the Sw/HeB/10/06 or Sw/TJ/1/07 virus. No considerable changes in the clinical presentation were observed post-inoculation in any of the virus-inoculated groups, and the viruses effectively replicated in the nasal cavity and lung tissue. Based on the results, it is possible that the new genotype of the swine H1N2 virus that emerged in China may become widespread in the swine population and pose a potential threat to public health.


      PubDate: 2015-01-16T17:22:48Z
       
  • Whole-genome sequence of a novel Chinese cyprinid herpesvirus 3 isolate
           reveals the existence of a distinct European genotype in East Asia
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Wei Li , Xuezhu Lee , Shaoping Weng , Jianguo He , Chuanfu Dong
      Cyprinid herpesvirus 3 (CyHV3), also known as koi herpesvirus (KHV), can be subdivided primarily into European and Asian genotypes, which are represented by CyHV3-U or CyHV3-I and CyHV3-J, respectively. In this study, the whole genome sequence of a novel Chinese CyHV3 isolate (GZ11) was determined and annotated. CyHV3-GZ11 genome was found to contain 295,119 nucleotides with 52.9% G/C content, which is highly similar to those of published CyHV3-U, CyHV3-I, and CyHV3-J strains. With reference to CyHV3-U, CyHV3-I, and CyHV3-J, CyHV3-GZ11 was also classified into 164 open reading frames (ORF), which include eight repeated ORFs. On the basis of the 12 alloherpeviruses core genes, results from phylogenetic analysis showed that CyHV3-GZ11 had closer evolutionary relationships with CyHV3-U and CyHV3-I than with CyHV3/KHV-J, which were also supported by genome wide-based single nucleotide substitution analysis and the use of a series of developed molecular markers. This study was the first to reveal the presence of a distinct European CyHV3 genotype in East and Southeast Asia at a whole genome level, which will evoke new insights on exploring the origin, evolution, and epidemiology of the virus.


      PubDate: 2015-01-16T17:22:48Z
       
  • Detection and genetic characterization of porcine group A rotaviruses in
           asymptomatic pigs in smallholder farms in East Africa: Predominance of
           P[8] genotype resembling human strains
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): J.O. Amimo , J.O. Junga , W.O. Ogara , A.N. Vlasova , M.N. Njahira , S. Maina , E.A. Okoth , R.P. Bishop , L.J. Saif , A. Djikeng
      Viral enteritis is a serious problem accounting for deaths in neonatal animals and humans worldwide. The absence of surveillance programs and diagnostic laboratory facilities have resulted in a lack of data on rotavirus associated diarrheas in pigs in East Africa. Here we describe the incidence of group A rotavirus (RVA) infections in asymptomatic young pigs in East Africa. Of the 446 samples examined, 26.2% (117/446) were positive for RVA. More nursing piglets (78.7%) shed RVA than weaned (32.9%) and grower (5.8%) pigs. RVA incidence was higher in pigs that were either housed_free-range (77.8%) or tethered_free-range (29.0%) than those that were free-range or housed or housed-tethered pigs. The farms with larger herd size (>10 pigs) had higher RVA prevalence (56.5%) than farms with smaller herd size (24.1–29.7%). This study revealed that age, management system and pig density significantly (p <0.01) influenced the incidence of RVA infections, with housed_free-range management system and larger herd size showing higher risks for RVA infection. Partial (811–1604nt region) sequence of the VP4 gene of selected positive samples revealed that different genotypes (P[6], P[8] and P[13]) are circulating in the study area with P[8] being predominant. The P[6] strain shared nucleotide (nt) and amino acid (aa) sequence identity of 84.4–91.3% and 95.1–96.9%, respectively, with known porcine and human P[6] strains. The P[8] strains shared high nt and aa sequence identity with known human P[8] strains ranging from 95.6–100% to 92–100%, respectively. The P[13] strains shared nt and aa sequence identity of 83.6–91.7% and 89.3–96.4%, respectively, only with known porcine P[13] strains. No P[8] strains yielded RNA of sufficient quality/quantity for full genome sequencing. However analysis of the full genome constellation of the P[6], two P[13] and one untypeable strains revealed that the P[6] strain (Ke-003-5) genome constellation was G26-P[6]-I5-R1-C1-M1-A8-N1-T1-E1-H1, P[13] strains (Ug-049 and Ug-453) had G5-P[13]-I5-R1-C1-M1-A8-N1-T7-E1-H1 while the untypeable strain (Ug-218) had G5-P[']-I5-R1-C1-M1-A8-N1-T1-E1-H' In conclusion, P[6] and P[8] genotypes detected were genetically closely related to human strains suggesting the possibility of interspecies transmission. Further studies are required to determine the role of RVA in swine enteric disease burden and to determine the genetic/antigenic heterogeneity of the circulating strains for development of accurate diagnostic tools and to implement appropriate prophylaxis programs.


      PubDate: 2015-01-16T17:22:48Z
       
  • Levels of feline infectious peritonitis virus in blood, effusions, and
           various tissues and the role of lymphopenia in disease outcome following
           experimental infection
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4
      Author(s): Niels C. Pedersen , Chrissy Eckstrand , Hongwei Liu , Christian Leutenegger , Brian Murphy
      Twenty specific pathogen free cats were experimentally infected with a virulent cat-passaged type I field strain of FIPV. Eighteen cats succumbed within 2–4 weeks to effusive abdominal FIP, one survived for 6 weeks, and one seroconverted without outward signs of disease. A profound drop in the absolute count of blood lymphocytes occurred around 2 weeks post-infection (p.i.) in cats with rapid disease, while the decrease was delayed in the one cat that survived for 6 weeks. The absolute lymphocyte count of the surviving cat remained within normal range. Serum antibodies as measured by indirect immunofluorescence appeared after 2 weeks p.i. and correlated with the onset of disease signs. Viral genomic RNA was either not detectable by reverse transcription quantitative real-time PCR (RT-qPCR) or detectable only at very low levels in terminal tissues not involved directly in the infection, including hepatic and renal parenchyma, cardiac muscle, lung or popliteal lymph node. High tissue virus loads were measured in severely affected tissues such as the omentum, mesenteric lymph nodes and spleen. High levels of viral genomic RNA were also detected in whole ascitic fluid, with the cellular fraction containing 10–1000 times more viral RNA than the supernatant. Replicating virus was strongly associated with macrophages by immunohistochemistry. Virus was usually detected at relatively low levels in feces and there was no evidence of enterocyte infection. Viral genomic RNA was not detected at the level of test sensitivity in whole blood, plasma, or the white cell fraction in terminal samples from the 19 cats that succumbed or in the single survivor. These studies reconfirmed the effect of lymphopenia on disease outcome. FIPV genomic RNA was also found to be highly macrophage associated within diseased tissues and effusions as determined by RT-qPCR and immunohistochemistry but was not present in blood.
      Graphical abstract image

      PubDate: 2015-01-16T17:22:48Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 25 February 2015
      Source:Veterinary Microbiology, Volume 175, Issues 2–4




      PubDate: 2015-01-16T17:22:48Z
       
  • A20 promotes Brucella intracellular growth via inhibition of macrophage
           cell death and activation
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Pan Wei , Guimei Cui , Qiang Lu , Li Yang , Zhenhong Guan , Wanchun Sun , Yuxi Zhao , Shuangxi Wang , Qisheng Peng
      The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of macrophage activation and apoptosis in tumor necrosis factor receptor1 (TNFR1) signaling pathway. Brucella infection can induce A20 expression in macrophages. Here, we hypothesize that A20 promotes Brucella intracellular growth via inhibition of activation and apoptosis of macrophages. To test this hypothesis, we stably incorporated mouse A20-shRNA into the RAW264.7 cells by lentiviral gene transfer to successfully knockdown A20. A20-deficient RAW264.7 cells were subsequently challenged with Brucella abortus and colony formation units (CFUs) of bacteria, TNFα production, NF-kB activation, macrophages apoptosis and cell death were evaluated. The A20 knockdown was shown to effectively promote B. abortus-stimulated TNFα release, NF-kB activation and macrophage cell death, which suppressed B. abortus intracellular replication. Unexpectedly, deficiency of A20 failed to lead to B. abortus-induced macrophage apoptosis. A20 deficiency coupled NF-kB inhibition promoted caspase-8 dependent B. abortus-induced macrophage apoptosis. These findings provide a novel mechanism by which Brucella intracellular growth within macrophages occurs through up-regulation of A20 thereby limiting activation and macrophages cell death.


      PubDate: 2015-01-11T21:18:26Z
       
  • Impact of mucin, bile salts and cholesterol on the virulence of Vibrio
           anguillarum towards gnotobiotic sea bass (Dicentrarchus labrax) larvae
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Xuan Li , Peter Bossier , Kristof Dierckens , Stanislas Laureau , Tom Defoirdt
      In this study, we investigated the impact of the host factors mucin, bile salts and cholesterol on the virulence of the economically important aquatic pathogen Vibrio anguillarum towards sea bass larvae. Pretreatment of V. anguillarum with either one of the host factors (at 10mgl−1) prior to inoculation into the sea bass rearing water increased virulence of the bacterium, although the effect of cholesterol was not significant. Each of the three host factors significantly increased several virulence-related phenotypes in V. anguillarum, i.e. protease activity, flagellar motility, biofilm formation and exopolysaccharide production, whereas there was no effect on growth of the bacterium under these conditions. Furthermore, the host factors increased the expression of genes involved in these phenotypes, i.e. the metalloprotease empA, the flagellar transcriptional regulator fleQ, the flagellin gene flaA, the chemotaxis methyltransferase gene cheR, the exopolysaccharide biosynthesis gene wbfD and the exopolysaccharide export gene wza. Our results indicate that V. anguillarum uses host mucin, bile salts, and cholesterol as cues to promote the expression of several important virulence traits that enhance the success of transmission from one host to another.


      PubDate: 2015-01-11T21:18:26Z
       
  • Changes in peripheral blood leucocytes of sheep experimentally infected
           with Mycoplasma agalactiae
    • Abstract: Publication date: Available online 10 December 2014
      Source:Veterinary Microbiology
      Author(s): Mariarosaria Marinaro , Grazia Greco , Elvira Tarsitano , Gianpiero Ventrella , Michele Camero , Marialaura Corrente , Giovanni Rezza , Domenico Buonavoglia
      Contagious agalactia is a serious disease of small ruminants affecting mainly mammary glands, joints and eyes. In sheep, the main aetiological agent is Mycoplasma agalactiae (Ma) whose abilities to persist in the target organs are known. Since there is no information on the effect of acute and chronic Ma infection on circulating leucocytes, the present study was designed to monitor granulocytes, monocytes, T and B lymphocytes, by flow cytometry, in female lactating sheep nasally infected with Ma. A profound depletion of leucocytes was observed from day 5 to day 34 post infection (p.i.). In particular, while the granulocytes returned to baseline levels by day 12 p.i., the monocytes remained significantly low until day 20 p.i. The infection caused a prolonged depletion of peripheral T lymphocytes (both CD4+ and CD8+) while B lymphocytes remained unaltered throughout the study. Mycoplasma agalactiae was detected by real-time PCR in several anatomical sites (ear, nose and milk) from day 2–5 p.i. until the end of the study (i.e., day 50 p.i.) while a transient bacteraemia was observed from day 5 to day 12 p.i. The leucopenia observed following intranasal Ma infection is likely due to leucocyte infiltration within the target organs.


      PubDate: 2015-01-11T21:18:26Z
       
  • Prevalence and characteristics of Cyprinid herpesvirus 3 (CyHV-3)
           infection in common carp (Cyprinus carpio L.) inhabiting three rivers in
           Kochi Prefecture, Japan
    • Abstract: Publication date: Available online 11 December 2014
      Source:Veterinary Microbiology
      Author(s): Hiroya Fujioka , Kenichi Yamasaki , Keiki Furusawa , Kazuki Tamura , Kazuki Oguro , Sumire Kurihara , Shingo Seki , Syun-ichirou Oshima , Masayuki Imajoh
      Cyprinid herpesvirus 3 (CyHV-3) causes lethal disease in common and koi carp. Mortality by CyHV-3 disease has not been reported since 2011 in Kochi Prefecture, Japan. Here, we detected and quantified CyHV-3 in common carp inhabiting three rivers in the prefecture to examine if the carp are carriers of CyHV-3 as a source of infection. CyHV-3 DNA was detected in 16.7% (12/72) of brain samples in Kagami River, 3.9% (3/76) of brain and 3.9% (3/76) of gill samples in Monobe River, and 5.1% (4/79) of brain and 1.3% (1/79) of gill samples in Wajiki River. CyHV-3 genotypes identified in the 23 samples were classified as the J genotype A1 that has been found in Japan. The CyHV-3 DNA load did not differ statistically between sampling months, indicating that CyHV-3 has been silent in common carp, unlike Lake Biwa where the annual reactivation occurs in spring. Taken together, our results represented definitive evidence that seasonal changes in water temperature do not affect CyHV-3 activity in carp. Considering that infectious virus was not isolated from CyHV-3 DNA-positive samples, it was suggested that CyHV-3 establishes a latent infection in carp populations inhabiting Kagami River, Monobe River and Wajiki River. Further, the presence of circular or concatameric CyHV-3 DNA was detected in five of 23 CyHV-3 DNA-positive samples. Common carp inhabiting Lake Biwa were reported previously to harbor linear but not circular CyHV-3 DNA. This difference suggested that the CyHV-3 genome may be circularized for long-term maintenance without active viral replication.
      Graphical abstract image

      PubDate: 2015-01-11T21:18:26Z
       
  • Identification of a novel herpesvirus in captive Eastern box turtles
           (Terrapene carolina carolina)
    • Abstract: Publication date: Available online 13 December 2014
      Source:Veterinary Microbiology
      Author(s): Richard R. Sim , Terry M. Norton , Ellen Bronson , Matthew C. Allender , Nancy Stedman , April L. Childress , James F.X. Wellehan Jr
      Herpesviruses are significant pathogens of chelonians which most commonly cause upper respiratory tract disease and necrotizing stomatitis. Herpesvirus infection was identified in two populations of captive Eastern box turtles (Terrapene carolina carolina) using histopathology and polymerase chain reaction (PCR) with DNA sequencing. Necrotizing lesions with eosinophilic to amphophilic intranuclear inclusion bodies were identified in the tissues of one hatch-year individual in January 2013, which was herpesvirus positive by PCR. A separate captive group of adults had an observed herpesvirus prevalence of 58% using PCR in July 2011. In these cases, a novel herpesvirus, Terrapene herpesvirus 1 (TerHV1), was identified and serves as the first herpesvirus sequenced in the genus Terrapene. Similar to the other herpesviruses of the Order Testudines, TerHV1 clusters with the genus Scutavirus of the subfamily Alphaherpesvirinae.


      PubDate: 2015-01-11T21:18:26Z
       
  • The use of quantitative PCR to detect Felis catus papillomavirus type 2
           DNA from a high proportion of queens and their kittens
    • Abstract: Publication date: Available online 11 December 2014
      Source:Veterinary Microbiology
      Author(s): N.A. Thomson , M. Dunowska , J.S. Munday
      Squamous cell carcinomas are common feline skin cancers that have been associated with infection with Felis catus papillomavirus type 2 (FcaPV-2). Currently, little is known about the epidemiology of FcaPV-2 infection. The aim of this study was to develop a real-time PCR assay to quantify FcaPV-2 DNA in plucked hairs and skin swabs from 11 healthy breeding queens and their kittens. Samples were taken prior to kittening and then 2, 7 and 28 days after kittening to determine the age at which the kittens were first exposed to the virus. FcaPV-2 DNA was amplified from all of the queens and from 91% of the kittens at 2 days of age. There was a wide range in the quantity of FcaPV-2 DNA detected, from 1 to 92,520 copies per swab, and from 0.01 to 234 copies per copy of reference gene DNA in the hair plucks. The quantity of FcaPV-2 DNA detected in samples collected from the kittens was strongly correlated to that of their respective queens and the mean viral DNA load was similar for cats within a household but varied significantly between households. This is the first time that quantitative PCR has been used to detect FcaPV-2 DNA and the results suggest that the virus is ubiquitous but there is a wide variation of viral DNA loads. Kittens appear to be exposed to FcaPV-2 early in life, presumably from direct contact with their queen. These results are important when determining if FcaPV-2 infection of cats is preventable.


      PubDate: 2015-01-11T21:18:26Z
       
  • Molecular characterisation of the Mycoplasma cynos haemagglutinin HapA
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Saša Kastelic , Ivanka Cizelj , Mojca Narat , Nataša Tozon , Victoria J. Chalker , Inna Lysnyansky , Joachim Spergser , Dušan Benčina
      Mycoplasma (M.) cynos is a proven pathogen of dogs causing respiratory infections including pneumonia. We examined 19 M. cynos strains isolated from different organs of dogs in Austria, Denmark and Israel. All strains agglutinated mammalian and chicken erythrocytes. Using erythrocytes of chickens or dogs as specific ligands we isolated an approximately 65kDa protein from cell-free supernatants of 3 M. cynos strains, which showed an apparent capacity for haemagglutination. The N-terminal sequence of a 25kDa fragment of this protein was identified as NNEMTPKVTVEAKSMELLLSVEK. The identical amino acid sequence is encoded by the gene MCYN_0308 in the genome of M. cynos C142. This gene belongs to a family of some 20 genes which encode putative lipoproteins with proline-rich regions (PRR) in the first third of their molecules. We termed the 65kDa haemagglutinin HapA and sequenced hapA gene homologues of 16 M. cynos strains. Analyses of hapA gene homologues revealed similar but not identical sequences, some having insertions and/or deletions in the PRR. We produced a recombinant HapA protein (rHapA) and also mouse monoclonal antibodies (mAbs) recognizing HapA. However, enzyme immunoassays using native M. cynos colonies and mAbs 5G2 or 3B7 showed variable expression of HapA in all M. cynos strains. This was further confirmed by Western blot analyses which showed different HapA quantities and also size-variation of HapA among strains. Analyses of cDNA of the expressed hapA genes showed that besides the hapA gene cultures of M. cynos (strains 105, 2002, 2297) can also express other forms of hap genes. In addition, in cloned cultures of strain 2297 altered HapA epitopes for mAbs 5G2 and 3B7 with distinct hapA gene mutations that resulted in altered HapA amino acid sequence were found. Most of the dogs examined had serum antibodies to rHapA. In conclusion, we characterized the M. cynos haemagglutinin HapA protein and encoding gene hapA, a factor involved in cytadherence to host cells and therefore important for M. cynos infection, and showed that expression of HapA is varied in M. cynos by two distinct mechanisms; differential gene expression and nucleic acid substitution within hapA homologues.


      PubDate: 2015-01-11T21:18:26Z
       
  • Application of cattle slurry containing Mycobacterium avium subsp.
           paratuberculosis (MAP) to grassland soil and its effect on the
           relationship between MAP and free-living amoeba
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): M. Salgado , M. Alfaro , F. Salazar , X. Badilla , E. Troncoso , A. Zambrano , M. González , R.M. Mitchell , M.T. Collins
      Slurry from dairy farms is commonly used to fertilize crops and pastures. This mixture of manure, urine and water can harbor multiple microbial pathogens among which Mycobacterium avium subsp. paratuberculosis (MAP) is a major concern. Persistence of MAP in soil and infection of soil Acanthamoeba was evaluated by culture, real-time IS900 PCR, and by staining of amoeba with acid-fast and vital stains comparing soils irrigated with MAP-spiked or control dairy farm slurry. MAP DNA was detected in soil for the 8 month study duration. MAP was detected by PCR from more soil samples for plots receiving MAP-spiked slurry (n =61/66) than from soils receiving control slurry ( n =10/66 samples). Vital stains verified that intracellular MAP in amoeba was viable. More MAP was found in amoeba at the end of the study than immediately after slurry application. There was no relationship between MAP presence in soil and in amoeba over time. Infection of amoeba by MAP provides a protected niche for the persistence and even possibly the replication of MAP in soils. As others have suggested, MAP-infected amoeba may act like a “Trojan horse” providing a means for persistence in soils and potentially a source of infection for grazing animals.


      PubDate: 2015-01-11T21:18:26Z
       
  • Mycoplasma gallisepticum in vivo induced antigens expressed during
           infection in chickens
    • Abstract: Publication date: Available online 18 December 2014
      Source:Veterinary Microbiology
      Author(s): Merav Ron , Anna Gorelick-Ashkenazi , Sharon Levisohn , Ran Nir-Paz , Steven J. Geary , Edan Tulman , Inna Lysnyansky , David Yogev
      Until now only a few genes encoding virulence factors have been characterized in the avian pathogen Mycoplasma gallisepticum. In order to identify candidate targets associated with infection we applied an immunoscreening technique—in vivo induced antigen technology (IVIAT)—to detect immunogens of M. gallisepticum strain Rlow expressed preferentially during in vivo infection. We identified 13 in vivo-induced (IVI) proteins that correspond to different functional categories including: previously reported putative virulence factors (GapA, PlpA, Hlp3, VlhA 1.07 and VlhA 4.01), transport (PotE, MGA_0241 and 0654), translation (L2, L23, ValS), chaperone (GroEL) and a protein with unknown function (MGA_0042). To validate the in vivo antigenic reactivity, 10 IVI proteins were tested by Western blot analysis using serum samples collected from chickens experimentally (with strain Rlow) and naturally (outbreaks, N =3) infected with M. gallisepticum. All IVI proteins tested were immunogenic. To corroborate these results, we tested expression of IVI genes in chickens experimentally infected with M. gallisepticum Rlow, and in MRC-5 human lung fibroblasts cell culture by using relative real time reverse-transcription PCR (RT-PCR). With the exception of MGA_0338, all six genes tested (MGA_1199, 0042, 0654, 0712, 0928 and 0241) were upregulated at least at one time point during experimental infection (2–4 week post-infection). In contrast, the expression of seven out of eight IVI genes (MGA_1199, 0152, 0338, 0042, 0654, 0712, 0928) were downregulated in MRC-5 cell culture at both 2 and 4h PI; MGA_0241 was upregulated 2h PI. Our data suggest that the identified IVI antigens may have important roles in the pathogenesis of M. gallisepticum infection in vivo.


      PubDate: 2015-01-11T21:18:26Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1




      PubDate: 2015-01-11T21:18:26Z
       
  • Muscovy duck reovirus infection rapidly activates host innate immune
           signaling and induces an effective antiviral immune response involving
           critical interferons
    • Abstract: Publication date: Available online 18 December 2014
      Source:Veterinary Microbiology
      Author(s): Zhilong Chen , Guifeng Luo , Quanxi Wang , Song Wang , Xiaojuan Chi , Yifan Huang , Haitao Wei , Baocheng Wu , Shile Huang , Ji-Long Chen
      Muscovy duck reovirus (MDRV) is a highly pathogenic virus in waterfowl and causes significant economic loss in the poultry industry worldwide. Because the host innate immunity plays a key role in defending against virus invasion, more and more attentions have been paid to the immune response triggered by viral infection. Here we found that the genomic RNA of MDRV was able to rapidly induce the production of interferons (IFNs) in host. Mechanistically, MDRV infection induced robust expression of IFNs in host mainly through RIG-I, MDA5 and TLR3-dependent signaling pathways. In addition, we observed that silencing VISA expression in 293T cells could significantly inhibit the secretion of IFNs. Remarkably, the production of IFNs was reduced by inhibiting the activation of NF-κB or knocking down the expression of IRF-7. Furthermore, our study showed that treatment of 293T cells and Muscovy duck embryo fibroblasts with IFNs markedly impaired MDRV replication, suggesting that these IFNs play an important role in antiviral response during the MDRV infection. Importantly, we also detected the induced expression of RIG-I, MDA5, TLR3 and type I IFN in Muscovy ducks infected with MDRV at different time points post infection. The results from in vivo studies were consistent with those in 293T cells infected with MDRV. Taken together, our findings reveal that the host can resist MDRV invasion by activating innate immune response involving RIG-I, MDA5 and TLR3-dependent signaling pathways that govern IFN production.


      PubDate: 2015-01-11T21:18:26Z
       
  • Hemagglutinin glycosylation modulates the pathogenicity and antigenicity
           of the H5N1 avian influenza virus
    • Abstract: Publication date: Available online 18 December 2014
      Source:Veterinary Microbiology
      Author(s): Xiaojian Zhang , Sujuan Chen , Yi Jiang , Kai Huang , Jun Huang , Da Yang , Jingjing Zhu , Yinbiao Zhu , Shaohua Shi , Daxin Peng , Xiufan Liu
      The location and number of glycosylation in HA proteins exhibit large variations among H5 subtype avian influenza viruses (AIVs). To investigate the effect of glycosylation in the globular head of HA on the pathogenicity and antigenicity of H5N1 AIVs, seven rescued AIVs differing in their glycosylation patterns (144N, 158N and 169N) within the HA globular head of A/Mallard/Huadong/S/2005 were generated using site directed mutagenesis. Results showed that loss of glycosylation 158N was the prerequisite for H5 AIV binding to the α2,6-linked receptor. Only in conjunction with the removal of the 158N glycosylation, the H5 AIVs harboring both 144N and 169N glycosylations obtained an optimal binding preference to the α2,6-linked receptor. Compared with the wild-type virus, growth of viruses lacking glycosylation at either 158N or 169N was significantly reduced both in MDCK and A549 cells, while replication of viruses with additional glycosylation 144N was significantly promoted. Mutant viruses with loss of 158N or 169N glycosylation sites showed increased pathogenicity, systemic spread and pulmonary inflammation in mice compared to the wild-type H5N1 virus. In addition, chicken studies demonstrated that inactivated de-glycosylation 169N mutant induced cross-reaction HI and neutralization antibody against various clades of H5N1 AIVs. Moreover, this type of glycan pattern vaccine virus provided better cross-protection in chickens compared to wild-type vaccine virus. Thus, the glycosylation alteration of HA should be considered in the global surveillance and vaccine design of H5 subtype AIVs.


      PubDate: 2015-01-11T21:18:26Z
       
  • Revisiting bovine pyometra—New insights into the disease using a
           culture-independent deep sequencing approach
    • Abstract: Publication date: Available online 19 December 2014
      Source:Veterinary Microbiology
      Author(s): Lif Rødtness Vesterby Knudsen , Cecilia Christensen Karstrup , Hanne Gervi Pedersen , Jørgen Steen Agerholm , Tim Kåre Jensen , Kirstine Klitgaard
      The bacteria present in the uterus during pyometra have previously been studied using bacteriological culturing. These studies identified Fusobacterium necrophorum and Trueperella pyogenes as the major contributors to the pathogenesis of pyometra. However, an increasing number of culture-independent studies have demonstrated that the bacterial diversity in most environments is underestimated in culture-based studies. Consequently, fastidious pyometra-associated pathogens may have been overlooked. Therefore, the primary purpose of this study was to investigate the diversity of bacteria in the uterus of cows with pyometra by using culture-independent 16S rRNA PCR combined with next generation sequencing. We investigated the microbial composition in the uterus of 21 cows with pyometra, which were obtained from a Danish slaughterhouse. Similar to the observations from the culture studies, Fusobacteriaceae, the family that F. necrophorum belongs to, was the operational taxonomic unit (OTU) observed in the largest quantities. By contrast, the Actinomycetaceae family, which includes T. pyogenes, constituted only 1% of the total number of reads. Thus we cannot confirm the previously reported role of species from this family in the pathogenesis of pyometra. Finally, we identified a large number of sequences representing three families of Gram-negative bacteria in the pyometra samples: Porphyromonadaceae, Mycoplasmataceae, and Pasteurellaceae. It is likely that these families comprise potential pathogenic species of a fastidious nature, which have been overlooked in previous studies. Our results increase the knowledge of the complexity of the pyometra microbiota and suggest that pathogens in addition to F. necrophorum may be involved in the pathogenesis of pyometra.


      PubDate: 2015-01-11T21:18:26Z
       
  • Association between animal age and the prevalence of Shiga toxin-producing
           Escherichia coli in a cohort of beef cattle
    • Abstract: Publication date: Available online 24 December 2014
      Source:Veterinary Microbiology
      Author(s): Raies A. Mir , Thomas A. Weppelmann , Minyoung Kang , Todd M. Bliss , Nicolas DiLorenzo , G. Cliff Lamb , Soohyoun Ahn , Kwang Cheol Jeong
      Even with advancements in pre- and post-harvest food safety, Shiga toxin-producing Escherichia coli (STEC) still present challenges to human health. Since cattle are the primary reservoir for STEC, lowering the prevalence of this pathogen in farm animals may reduce STEC outbreaks in humans. However, because many of the factors that modulate the colonization and persistence of STEC in cattle remain unknown, reducing STEC in this host is challenging. In this study, we evaluated a cohort of beef cattle one to eleven years of age to determine the effect of animal age on the prevalence of STEC. During the first year of sample collection, heifers had significantly lower STEC prevalence than cows (37.5% vs. 70%). In the second year of sample collection, STEC prevalence peaked in cows that were two years of age and tended to decrease as animals became older. In addition, by studying a subset of the animals in both years, we observed an increase in STEC prevalence from 40.6% to 53.1% in heifers, whereas cows had a net decrease in STEC prevalence from 71.4% to 61.9%. The results from this study indicate that animal age is a significant factor that influences the prevalence of STEC in cattle. These findings have implications for the development of on-farm mitigation strategies by targeting animals with the highest risk of shedding; it could be possible to reduce pathogen transmission among cattle and prevent zoonotic or foodborne transmission to humans.


      PubDate: 2015-01-11T21:18:26Z
       
  • DNA vaccine against infectious bursal disease virus: Still more to explore
    • Abstract: Publication date: Available online 24 December 2014
      Source:Veterinary Microbiology
      Author(s): Sachin Kumar



      PubDate: 2015-01-11T21:18:26Z
       
  • Novel reassortant H5N5 viruses bind to a human-type receptor as a factor
           in pandemic risk
    • Abstract: Publication date: Available online 24 December 2014
      Source:Veterinary Microbiology
      Author(s): Qunhui Li , Xuan Wang , Zhao Gao , Zhongtao Sun , Zhu Cui , Zhiqiang Duan , Juan Li , Min Gu , Xiaoquan Wang , Jiao Hu , Xiaowen Liu , Xiufan Liu
      Highly pathogenic avian influenza A(HPAI) H5N1 viruses pose a serious pandemic threat due to their virulence and high mortality in humans, and their increasingly expanding host range and significant ongoing evolution could enhance their human-to-human transmissibility. Recently, various reassortant viruses were detected in different domestic poultry, with the HA gene derived from the A/goose/Guangdong/1/96-like (Gs/GD-like) lineage and the NA gene from influenza viruses of other subtypes. It is reported that some natural reassortant H5N5 highly pathogenic avian influenza viruses were isolated from poultry in China. And their HA genes were belonged to a new clade 2.3.4.4. We evaluated the receptor binding property and transmissibility in guinea pigs of these reassortant H5N5 HPAIVs. The results showed that these viruses bound to both avian-type (α-2,3) and human-type (α-2,6) receptors. In addition, we found that one of these viruses, 031, not only replicated but also transmitted efficiently in guinea pigs. Therefore, such reassortant influenza viruses may pose a pandemic threat.


      PubDate: 2015-01-11T21:18:26Z
       
  • Serological evidence of avian influenza virus and canine influenza virus
           infections among stray cats in live poultry markets, China
    • Abstract: Publication date: Available online 27 December 2014
      Source:Veterinary Microbiology
      Author(s): Han Zhou , Shu-yi He , Lingshuang Sun , Huamei He , Fangxiao Ji , Yao Sun , Kun Jia , Zhangyong Ning , Heng Wang , Liguo Yuan , Pei Zhou , Guihong Zhang , Shoujun Li
      From January 2010 to January 2012, we collected sera samples from 700 stray cats living in close proximity to poultry farms or poultry markets in 4 provinces in China. A number of cats had evidence of avian and canine influenza virus infection: avian H9N2 [24 by HI ≥1:20 and 16 by microneutralization (MN) assay ≥1:80]; avian H5N1 (9 by HI ≥1:20 and 3 by MN assay ≥1:80) and canine H3N2 (32 by HI ≥1:20 and 18 by MN ≥1:80). Bivariate analyses revealed that cats sampled near live poultry markets and cats with influenza-like-illness were at increased risk of having elevated antibody titers by HI against avian H9N2, avian H5N1, or canine H3N2 viruses. Hence, cats may play a very important role in the ecology of novel influenza viruses and periodic epidemiological surveillance for novel influenza infections among stray cats could serve as an early warning system for human threats.


      PubDate: 2015-01-11T21:18:26Z
       
  • Corrigendum to “Genetic characterization of hepadnaviruses
           associated with histopathological changes in the liver of duck and goose
           embryos” [Vet. Microbiol. 174 (2014) 302–308]
    • Abstract: Publication date: Available online 6 January 2015
      Source:Veterinary Microbiology
      Author(s): Marina Biđin , Marina Tišljar , Zdenko Biđin , Ivana Lojkić , Darko Majnarić



      PubDate: 2015-01-11T21:18:26Z
       
  • Effect of booster shot and investigation of vaccination efficacy period
           against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius
           auratus
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Takafumi Ito , Yukio Maeno
      In this study, the efficacy period of an intraperitoneal vaccination and effect of a booster shot of vaccine against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus were investigated. Cell culture supernatant of cyprinid herpesvirus 2 (CyHV-2), causative agent of HVHN, propagated in goldfish fin (GFF) cells was inactivated with formalin (0.1%, v/v) for 2 days at 4°C. Three groups of the variety Ryukin were individually intraperitoneally injected with the vaccine and each group was separately maintained in replicate tanks. After 4 weeks (Vaccinated-4w-1 and 2) and 8 weeks (Vaccinated-8w-1 and 2) from the first vaccination, the fish were CyHV-2-challenged by the immersion route (10 TCID50 l−1). In addition, the other vaccinated group of fish were injected with a booster vaccine 4 weeks after the first vaccination as the Vaccinated-booster groups, then the fish of these groups were CyHV-2-challenged by the immersion route (10 TCID50 l−1) after 8 weeks from the first vaccination. The mean of the relative percentage survival (RPS) values of the Vaccinated-4w and 8w groups showed 42.5% and 57.6%, respectively. In addition, the mean RPS value of Vaccinated-booster groups showed 63.6%. Statistical analysis showed significantly higher survival rates in all the vaccinated groups than those of the respective negative control groups using Fisher's exact test. Moreover, the survival rates of vaccinated-booster groups were significantly higher (p =0.036) compared with the respective control groups by Student's t test. The present study shows the efficacy period of the vaccine is at least 8 weeks and a booster shot showed a tendency to enhance the protection against HVHN in goldfish.


      PubDate: 2015-01-11T21:18:26Z
       
  • Pseudomonas fluorescens: Fur is required for multiple biological
           properties associated with pathogenesis
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ze-jun Zhou , Lu Zhang , Li Sun
      Pseudomonas fluorescens, a Gram-negative bacterium, is an aquaculture pathogen with a broad host range. In a previous study, we had demonstrated that knockout of the fur gene of a pathogenic P. fluorescens strain, TSS, resulted in profound virulence attenuation. In this work, we studied the properties of the fur knockout mutant, TFM, in comparison with the wild type strain TSS. We found that compared to TSS, TFM (i) was impaired in siderophore production and extracellular enzyme activities, (ii) exhibited altered global polarity, (iii) was dramatically reduced in the ability to resist oxidative stress, (iv) showed higher tolerance to manganese, and (v) exhibited significantly reduced cytotoxicity. When incubated with cultured host cells, TFM displayed a cellular binding index much lower than that of TSS. Neither TFM nor TSS was able to survive and replicate in host cells. Following inoculation into Japanese flounder (Paralichthys olivaceus), TSS upregulated the expression of a wide range of genes involved in innate immunity, notably IL-1β and two CC chemokines. In contrast, TFM caused significant inductions of only a few genes and to much lower magnitudes than TSS. Given the strong inductions of IL-1β and the two chemokines by TSS, the effect of these three genes on P. fluorescens invasion was examined. The results showed that overexpression of these genes in flounder significantly inhibited TSS dissemination into and colonization of host tissues. Taken together, these results indicate that Fur is required for multiple processes associated with virulence, and that proinflammatory cytokines and chemokines likely play important roles in the clearance of P. fluorescens infection.


      PubDate: 2015-01-11T21:18:26Z
       
  • Fine mapping and conservation analysis of linear B-cell epitopes of peste
           des petits ruminants virus nucleoprotein
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ruisong Yu , Xiaoming Fan , Wanxiang Xu , Wentao Li , Shijuan Dong , Yumin Zhu , Yaping He , Haiping Tang , Rong Du , Zhen Li
      Nucleoprotein (NP) is the most abundant and highly immunogenic protein of morbillivirus, and is presently the basis of most diagnostic assays for peste des petits ruminants virus (PPRV). In this study, fine epitope mapping and conservation analysis of linear B-cell epitopes on the PPRV NP has been undertaken using biosynthetic peptides. Nineteen linear B-cell epitopes were identified and their corresponding minimal motifs were located on the NP of PPRV China/Tibet/Geg/07-30. Conservation analysis indicated that ten of the 19 minimal motifs were conserved among 46 PPRV strains. Peptides containing the minimal motifs were recognized using anti-PPRV serum from a goat immunized with PPRV vaccine strain Nigeria 75/1. Identified epitopes and their motifs improve our understanding of the antigenic characteristics of PPRV NP and provide a basis for the development of epitope-based diagnostic assays.


      PubDate: 2015-01-11T21:18:26Z
       
  • Characterization of Mannheimia haemolytica biofilm formation in vitro
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ismail Boukahil , Charles J. Czuprynski
      Mannheimia haemolytica is the primary bacterial agent in the bovine respiratory disease complex. It is thought that M. haemolytica colonizes the tonsillar crypts of cattle as a commensal and subsequently descends into the lungs to cause disease. Many bacterial species persist in the host as biofilms. There is limited information about the ability of M. haemolytica to form biofilms. The aim of this study was to develop an in vitro model for M. haemolytica biofilm formation. We found that M. haemolytica required at least 36h to form robust biofilms on plastic in vitro when incubated in RPMI-1640 tissue culture medium at 37°C, with maximal biofilm formation being evident at 48h. Biofilm formation was inhibited by adding the monosaccharides d(+) galactose and d(+) mannose to the growth medium. Addition of antibodies to the M. haemolytica surface protein OmpA also reduced biofilm formation. Upon evaluating the macromolecules within the biofilm extracellular polymeric substance we found it contained 9.7μg/cm2 of protein, 0.81μg/cm2 of total carbohydrate, and 0.47μg/cm2 of extracellular DNA. Furthermore, proteinase K treatment significantly decreased biofilms (P <0.05) while α-amylase and micrococcal nuclease decreased biofilms to a lesser extent. M. haemolytica biofilm cells were more resistant than planktonic cells to the antibiotics florfenicol, gentamicin, and tulathromycin. These results provide evidence that M. haemolytica can form biofilms, which could contribute to its ability to persist as a commensal in the bovine upper respiratory tract.


      PubDate: 2015-01-11T21:18:26Z
       
  • Influence of the major nitrite transporter NirC on the virulence of a
           Swollen Head Syndrome Avian Pathogenic E. coli (APEC) strain
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Jacqueline Boldrin de Paiva , Janaína Luisa Leite , Livia Pilatti Mendes da Silva , Thais Cabrera Galvão Rojas , Fernanda de Pace , Rogério Arcuri Conceição , Vanessa Sperandio , Wanderley Dias da Silveira
      Avian Pathogenic Escherichia coli (APEC) strains are extra-intestinal E. coli that infect poultry and cause diseases. Nitrite is a central branch-point in bacterial nitrogen metabolism and is used as a cytotoxin by macrophages. Unlike nitric oxide (NO), nitrite cannot diffuse across bacterial membrane cells. The NirC protein acts as a specific channel to facilitate the transport of nitrite into Salmonella and E. coli cells for nitrogen metabolism and cytoplasmic detoxification. NirC is also required for the pathogenicity of Salmonella by downregulating the production of NO by the host macrophages. Based on an in vitro microarray that revealed the overexpression of the nirC gene in APEC strain SCI-07, we constructed a nirC-deficient SCI-07 strain (ΔnirC) and evaluated its virulence potential using in vivo and in vitro assays. The final cumulative mortalities caused by mutant and wild-type (WT) were similar; while the ΔnirC caused a gradual increase in the mortality rate during the seven days recorded, the WT caused mortality up to 24h post-infection (hpi). Counts of the ΔnirC cells in the spleen, lung and liver were higher than those of the WT after 48hpi but similar at 24hpi. Although similar number of ΔnirC and WT cells was observed in macrophages at 3hpi, there was higher number of ΔnirC cells at 16hpi. The cell adhesion ability of the ΔnirC strain was about half the WT level in the presence and absence of alpha-d-mannopyranoside. These results indicate that the nirC gene influences the pathogenicity of SCI-07 strain.


      PubDate: 2015-01-11T21:18:26Z
       
  • Divergence of a strain of Pseudomonas aeruginosa during an outbreak of
           ovine mastitis
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Elli A. Wright , Valeria Di Lorenzo , Claudia Trappetti , Manuele Liciardi , Germano Orru , Carlo Viti , Christina Bronowski , Amanda J. Hall , Alistair C. Darby , Marco R. Oggioni , Craig Winstanley
      Bacterial infections causing mastitis in sheep can result in severe economic losses for farmers. A large survey of milk samples from ewes with mastitis in Sardinia, Italy, indicated an increasing prevalence of Pseudomonas aeruginosa infections. It has been shown previously that during chronic, biofilm-associated infections P. aeruginosa populations diversify. We report the phenotypic and genomic characterisation of two clonal P. aeruginosa isolates (PSE305 and PSE306) from a mastitis infection outbreak, representing distinct colony morphology variants. In addition to pigment production, PSE305 and PSE306 differed in phenotypic characteristics including biofilm formation, utilisation of various carbon and nitrogen sources, twitching motility. We found higher levels of expression of genes associated with biofilm formation (pelB) and twitching motility (flgD) in PSE305, compared to the biofilm and twitching-defective PSE306. Comparative genomics analysis revealed single nucleotide polymorphisms (SNPs) and minor insertion/deletion variations between PSE305 and PSE306, including a SNP mutation in the pilP gene of PSE306. By introducing a wild-type pilP gene we were able to partially complement the defective twitching motility of PSE306. There were also three larger regions of difference between the two genomes, indicating genomic instability. Hence, we have demonstrated that P. aeruginosa population divergence can occur during an outbreak of mastitis, leading to significant variations in phenotype and genotype, and resembling the behaviour of P. aeruginosa during chronic biofilm-associated infections.


      PubDate: 2015-01-11T21:18:26Z
       
  • Multiple sampling and discriminatory fingerprinting reveals clonally
           complex and compartmentalized infections by M. bovis in cattle
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Yurena Navarro , Beatriz Romero , María Francisca Copano , Emilio Bouza , Lucas Domínguez , Lucía de Juan , Darío García-de-Viedma
      The combination of new genotyping tools and a more exhaustive sampling policy in the analysis of infection by Mycobacterium tuberculosis has shown that infection by this pathogen is more complex than initially expected. Mixed infections, coexistence of clonal variants from a parental strain, and compartmentalized infections are all different modalities of this clonal complexity. Until recently, genotyping of Mycobacterium bovis in animal populations was based on spoligotyping and analysis of a single isolate per infection; therefore, clonal complexity is probably underdetected. We used multiple sampling combined with highly discriminatory MIRU-VNTR to study compartmentalized infections by M. bovis in a low-tuberculosis prevalence setting. We spoligotyped the M. bovis isolates from two or more anatomic locations sampled from 55 animals on 39 independent farms. Compartmentalized infections, with two different strains infecting independent lymph nodes in the same animal, were found in six cases (10.9%). MIRU-VNTR analysis confirmed that the compartmentalization was strict and that only one strain was present in each infected node. MIRU-VNTR analysis of additional infected animals on one of the farms confirmed that the compartmentalized infection was a consequence of superinfection, since the two strains were independently infecting other animals. This same analysis revealed the emergence of a microevolved clonal variant in one of the lymph nodes of the compartmentalized animal. Clonal complexity must also be taken into consideration in M. bovis infection, even in low-prevalence settings, and analyses must be adapted to detect it and increase the accuracy of molecular epidemiology studies.


      PubDate: 2015-01-11T21:18:26Z
       
  • Multilocus sequence typing of Mycoplasma bovis reveals host-specific
           genotypes in cattle versus bison
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Karen B. Register , Luke Thole , Ricardo F. Rosenbush , F. Chris Minion
      Mycoplasma bovis is a primary agent of mastitis, pneumonia and arthritis in cattle and the bacterium most frequently isolated from the polymicrobial syndrome known as bovine respiratory disease complex. Recently, M. bovis has emerged as a significant health problem in bison, causing necrotic pharyngitis, pneumonia, dystocia and abortion. Whether isolates from cattle and bison comprise genetically distinct populations is unknown. This study describes the development of a highly discriminatory multilocus sequencing typing (MLST) method for M. bovis and its use to investigate the population structure of the bacterium. Genome sequences from six M. bovis isolates were used for selection of gene targets. Seven of 44 housekeeping genes initially evaluated were selected as targets on the basis of sequence variability and distribution within the genome. For each gene target sequence, four to seven alleles could be distinguished that collectively define 32 sequence types (STs) from a collection of 94 cattle isolates and 42 bison isolates. A phylogeny based on concatenated target gene sequences of each isolate revealed that bison isolates are genetically distinct from strains that infect cattle, suggesting recent disease outbreaks in bison may be due to the emergence of unique genetic variants. No correlation was found between ST and disease presentation or geographic origin. MLST data reported here were used to populate a newly created and publicly available, curated database to which researchers can contribute. The MLST scheme and database provide novel tools for exploring the population structure of M. bovis and tracking the evolution and spread of strains.


      PubDate: 2015-01-11T21:18:26Z
       
  • Emission of ESBL/AmpC-producing Escherichia coli from pig fattening farms
           to surrounding areas
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Christina von Salviati , Henriette Laube , Beatriz Guerra , Uwe Roesler , Anika Friese
      The presence of ESBL/AmpC-producing Escherichia coli in livestock such as pigs has been known for some time. However, to date there is little information about the transmission of these resistant bacteria between pig farms and their surroundings. Thus, the aim of this study was to explore this topic by investigating seven German pig fattening farms. Samples from outside (including ground surfaces, ambient air, slurry and digestate from biogas plants) and, in parallel, from inside the pig barns (including pig feces, dust, barn air, flies and mice feces) were examined for ESBL/AmpC-producing E. coli and selected isolates were compared by pulsed-field gel electrophoresis (PFGE) analysis. 14/17 (82.4%) slurry samples and three of four samples of digestate from biogas plants tested positive for ESBL/AmpC-producing E. coli. In the vicinity of the pig barns these resistant bacteria were detected in 14/87 (16.1%) boot swabs taken from various ground surfaces and in 2/36 (6%) ambient air samples. Inside the pig barns, 6/63 (9.5%) barn air samples and a small proportion of flies and mice feces samples were ESBL/AmpC-positive. PFGE analysis proved fecal emission as well as a possible spread via flies, as identical ESBL-E. coli isolates were detected in slurry and on fertilized fields, as well as in flies and pooled feces from inside the barn and slurry. Contaminated slurry presented the major emission source for ESBL/AmpC-producing E. coli in the pig fattening farms, but a spread via the airborne route or via different vectors also seems possible.


      PubDate: 2015-01-11T21:18:26Z
       
  • High-level fluoroquinolone resistant Salmonella enterica serovar Kentucky
           ST198 epidemic clone with IncA/C conjugative plasmid carrying blaCTX-M-25
           gene
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Dariusz Wasyl , Izabela Kern-Zdanowicz , Katarzyna Domańska-Blicharz , Magdalena Zając , Andrzej Hoszowski
      Multidrug resistant Salmonella Kentucky strains have been isolated from turkeys in Poland since 2009. Multiple mutations within chromosomal genes gyrA and parC were responsible for high-level ciprofloxacin resistance. One of the isolates was extended spectrum β-lactamase- (ESBL) positive: the strain 1643/2010 carried a conjugative 167,779bps plasmid of IncA/C family. The sequence analysis revealed that it carried a bla CTX-M-25 gene and an integron with another β-lactamase encoding gene—bla OXA-21. This is the first known report of a CTX-M-25 encoding gene both in Poland and in Salmonella Kentucky world-wide, as well as in the IncA/C plasmid. Analysis of the integron showed a novel arrangement of gene cassettes—aacA4, aacC-A1 and bla OXA-21 where the latter might result from an intergeneric gene transfer. The study confirmed Salmonella Kentucky population isolated in Poland belongs to global epidemics of high level fluoroquinolone resistant clone ST198 that can carry rare β-lactamase genes.


      PubDate: 2015-01-11T21:18:26Z
       
  • Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida
           link isolates with their geographical origins
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Jean-Guillaume Emond-Rheault , Antony T. Vincent , Mélanie V. Trudel , Francis Brochu , Brian Boyle , Katherine H. Tanaka , Sabrina A. Attéré , Éric Jubinville , Thomas P. Loch , Andrew D. Winters , Mohamed Faisal , Michel Frenette , Nicolas Derome , Steve J. Charette
      Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium.


      PubDate: 2015-01-11T21:18:26Z
       
  • Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce
           inflammation and apoptosis in porcine peripheral blood mononuclear cells
           in vitro
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Fangfang Bai , Bo Ni , Maojun Liu , Zhixin Feng , Qiyan Xiong , Guoqing Shao
      Mycoplasma hyopneumoniae is the causative agent of swine enzootic pneumonia (EP), a disease that causes considerable economic losss in swine industry. Lipid-associated membrane proteins (LAMPs) of mycoplasma play important roles in causing mycoplasma diseases. The present study explores the pathogenic mechanisms of M. hyopneumoniae LAMPs by elucidating their role in modulating the inflammation, apoptosis, and relevant signaling pathways of peripheral blood mononuclear cells (PBMCs) of pig. LAMP treatment inhibited the growth of PBMCs. Up-regulation of cytokines, such as IL-6 and IL-1β, as well as increased production of nitric oxide (NO) and superoxide anion were all detected in the supernatant of LAMPs-treated PBMCs. Furthermore, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMPs of M. hyopneumoniae induced a time-dependent apoptosis in lymphocyts and monocytes from PBMCs, which was blocked by NOS inhibitor or antioxidant. In addition, LAMPs induced the phosphorylation of p38, the ratio of pro-apoptotic Bax protein to anti-apoptotic Bcl-2, activation of caspase-3 and caspase-8, and poly ADP-ribose polymerase (PARP) cleavage in PBMCs. These findings demonstrated that M. hyopneumoniae LAMPs induced the production of proinflammatory cytokines, NO and reactive oxygen species (ROS), and apoptosis of PBMCs in vitro through p38 MAPK and Bax/Bcl-2 signaling pathways, as well as caspase activation.


      PubDate: 2015-01-11T21:18:26Z
       
  • Serological relationships among subgroups in bovine viral diarrhea virus
           genotype 1 (BVDV-1)
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Gizem Alpay , Kadir Yeşilbağ
      Bovine viral diarrhea virus (BVDV) has various economic impacts associated with diarrhea, poor performance, an increase in the frequency of other infections and lethal outcomes. Both genotypes, namely BVDV-1 and BVDV-2, as well as different subgroups within these genotypes have been reported worldwide. Understanding the serological differences among the BVDV subgroups is important for disease epidemiology and prevention as well as vaccination programs. The aim of this study was to determine the serological relatedness among the subgroups in BVDV-1. For that purpose, sheep hyperimmune sera were collected against representative strains from 6 of the subgroups of BVDV-1 (BVDV-1a, -1b, -1d, -1f, -1h and -1l). The serum samples that gave the peak antibody titer to the homologous strains were used to perform cross neutralization assays. The highest homologous antibody titer (1:5160) was obtained against BVDV-1h. Regarding the cross neutralizing (heterologous) antibodies, the lowest titer (1:20) was produced by the BVDV-1f antiserum against the BVDV-1a and BVDV1-b viruses. The highest cross neutralizing titer (1:2580) achieved by the BVDV-1h antiserum was against the BVDV-1b strain. The cross neutralization results indicated particular serological differences between the recently described subgroup (BVDV-1l) and BVDV-1a/-1b, which are widely used in commercial vaccines. Considering the cross neutralization titers, it is concluded that selected BVDV-1l and BVDV-1h strains can be used for the development of diagnostic and control tools.


      PubDate: 2015-01-11T21:18:26Z
       
  • Vaccination with a genotype 1 modified live vaccine against porcine
           reproductive and respiratory syndrome virus significantly reduces viremia,
           viral shedding and transmission of the virus in a quasi-natural
           experimental model
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Emanuela Pileri , Elisa Gibert , Ferran Soldevila , Ariadna García-Saenz , Joan Pujols , Ivan Diaz , Laila Darwich , Jordi Casal , Marga Martín , Enric Mateu
      The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n =40) and NV (n =58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p <0.05). Vaccination shortened viremia (12.2±4 versus 3.7±3.4 days in NV and V pigs, respectively, p <0.01). The 50% survival time for becoming infected (Kaplan–Meier) for V was 21 days (CI95% =14.1–27.9) compared to 7 days (CI95% =5.2–8.7) for NV animals (p <0.01). These differences were reflected in the R value as well: 2.78 (CI95% =2.13–3.43) for NV and 0.53 (CI95% =0.19–0.76) for V pigs (p <0.05). All sentinel pigs (10/10) in pens adjacent to NV+SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V+SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.


      PubDate: 2015-01-11T21:18:26Z
       
  • Effects of different NS genes of avian influenza viruses and amino acid
           changes on pathogenicity of recombinant A/Puerto Rico/8/34 viruses
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Il-Hwan Kim , Hyuk-Joon Kwon , Su-Hyung Lee , Dae-Yong Kim , Jae-Hong Kim
      To examine the effects of the NS1 and NEP genes of avian influenza viruses (AIVs) on pathogenicity in mice, we generated recombinant PR8 viruses containing 3 different NS genes of AIVs. In contrast to the reverse genetics-generated PR8 (rPR8) strain and other recombinant viruses, the recombinant virus rPR8-NS(0028), which contained the NS gene of A/chicken/KBNP-0028/2000 (H9N2) (0028), was non-pathogenic to mice. The novel single mutations of 0028 NS1 to corresponding amino acid of PR8 NS1, G139D and S151T increased the pathogenicity of rPR8-NS(0028). The replacement of the PL motifs (EPEV or RSEV) of pathogenic recombinant viruses with that of 0028 (GSEV) did not reduce the pathogenicity of the viruses. However, a recombinant virus with an EPEV-grafted 0028 NS gene was more pathogenic than rPR8-NS(0028) but less than rPR8. The lower pathogenicity of rPR8-NS(0028) might be associated with the lower virus titer and IFN-β level in the lungs of infected mice, and be attributed to G139, S151 and GSEV-PL motif of NS1 gene of 0028. In conclusion we defined new amino acid residues of NS1 related to mice pathogenicity and the presence of pathogenic NS genes among low pathogenic AIVs may encourage continuous monitoring of their mammalian pathogenicity.
      Graphical abstract image

      PubDate: 2015-01-11T21:18:26Z
       
 
 
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